The frequency and energy ranges of photons in some parts of the electromagnetic spectrum are given in the table above. Which of the following could be the energy of a photon in the visible range?

The correct answer is "4 x 10 -19 J".

Explanation:

The missing options of this question are:

9 x 10-21 J

4 x 10-20 J

4 x 10-19 J

9 x 10-19 J

The correct answer is "4 x 10-19 J".

The energy of a photon is given by the wavelength of the photon, where the lower the wavelength the higher the energy is. Therefore, photons in the infrared range have the lowest energy and photons in the ultraviolet range have the highest energy. A photon in the visible range must have an energy which is between the infrared range and the ultraviolet range. Since the maximum energy of a photon in the infrared range is 3 x 10-19 J and the minimum energy of a photon in the ultraviolet range is 5 x 10-19 J, a photon in the visible range could have an energy of 4 x 10-19 J.